Con Coughlin is the Telegraph's Defence Editor and a world-renowned expert on global security and terrorism issues. He is the author of several critically acclaimed books. His new book, Churchill's First War: Young Winston and the fight against the Taliban, is published by Macmillan in London and Thomas Dunne Books in New York. He appears regularly on radio and television in Britain and America.

Ehud Olmert tells Gordon Brown the rules of the Middle East

By all accounts the breakfast meeting today between Ehud Olmert, the Israeli Prime Minister, and Gordon Brown was a friendly affair that ended with the outgoing leader being introduced to all the members of Mr Brown's cabinet. But when it got down to the serious business of discussing the current state of play in the Middle East the bonhomie quickly faded when Mr Brown requested that Mr Olmert ease Israel's blockade of the Gaza Strip, which aid agencies claim is on the verge of a Zimbabwe-style humanitarian disaster.

The reason the Israelis have taken this extreme action is that the Iranian-backed Hamas militants that now control Gaza have recently taken to firing barrages of home-made rockets at nearby Israeli residential areas, forcing thousands of Israeli civilians to flee their homes. This is the thanks Israel gets for unilaterally withdrawing its forces from Gaza three years ago and giving the Palestinians responsibility for running their own affairs.

Mr Olmert made clear to Mr Brown that the aid agencies' predictions for Gaza have been over-exaggerated, and that he has no intention of easing the blockade so long as Hamas continues to threaten Israel, thereby giving Mr Brown a sharp lesson in the real rules of engagement that dominate the Middle East.

Although Mr Olmert will soon be obliged to leave office to deal the mountain of corruption allegations he faces from his political opponents, he has nevertheless expended much energy during the course of the last year trying to hammer out a deal with the Palestinians on the basis of the well-established rules of engagement that have been established during decades of negotiations. The fundamental requirement of the Israelis is to have their future security guaranteed, while the Palestinians yearn for independence from Israeli rule and a state they can call home.

Mr Olmert believes he has thrashed out the principles of an agreement with his Palestinian opposite number, Mahmoud Abbas, which could form the basis for a lasting agreement. Unfortunately time is not on his side, and much as he would like to conclude a deal with Mr Abbas before he leaves office next February, Mr Olmert will nevertheless leave a legacy that both Mr Brown and Barack Obama, the new American president, would do well to use as the basis for their own efforts to resolve this conflict once and for all.